Granular laundry detergent compositions of today may contain detergent granules formed either by agglomeration process or by spray drying process. The agglomeration process can produce detergent granules with higher bulk density and higher concentrations of cleaning actives or surfactants than typical detergent granules that are formed by the spray drying process. Such high density, high active detergent granules are particularly useful for forming laundry detergents that are more compacted in size with smaller mass and volume, which directly translate into end benefits such as environmental friendliness, more cost-effective packaging and shipping, and improved efficiency of the product's commercial supply chain. Further, the agglomeration process has a significantly lower carbon footprint in comparison with the spray drying process and is therefore particularly desirable for making laundry detergent products of long term environment sustainability.
However, the high density, high active agglomerated detergent granules have been known to suffer from slow dissolution in water. The slower dissolution of such agglomerated detergent granules makes them particularly unsuitable for suboptimal washing conditions, such as, for example, hand-washing conditions where the water temperature is relatively lower, the amount of water used for washing is relatively smaller, and the washing cycle is relatively shorter, in comparison with machine washing conditions.
Despite the fast growing population of washing machine users, hand-washing fabric is still a prevalent laundering practice in a majority of the developing countries in the world, and there is therefore a continuing need for high density, high active detergent granules with improved dissolution profile suitable for forming laundry detergent products that are suitable for suboptimal washing conditions.
Further, consumers who hand-wash fabric view copious suds in the wash as the primary and most desirable signal of cleaning. High suds volume is especially desirable during hand washing of fabrics, since the consumer can directly feel and touch the suds generated during the wash cycle and intuitively correlates the high suds volume with the achievement of sufficient fabric cleaning. However, it is costly to add more surfactant into the detergent composition in order to generate a consumer-delighting amount of suds during the wash, and additional surfactant renders the detergent composition harsh to the consumer's hands and also requires a larger amount of water to rinse off during the rinse cycle, which can be a limitation for regions where water is scarce. Therefore, there is also a need for detergent compositions capable of generating more suds during the wash, but without increasing the surfactant level therein.